Sound deadner

[smitty2919]

New guy on here looking for some suggestions/opinions on sound deadener. Can anyone point me to some place to find out about it? I have a 03 Mach 1 and with the loud exhaust I have, I'm looking to quiet down the interior.

I have talked to Second Skin (Max) and have realized the need and use for both Damplifier and Luxury Liner. I have been getting mixed opinions whether to just go with Peel and Seal as panel vibration reducer and Luxury Liner Pro for air born noise reducer...

I have bene hearing about this site and thought it would be a good place to get some answer...Another thing is people have posted before and after results, but I don't know how credible they are. The conditions of the before and after test etc.

I'm a mechanical engineer, so I understand the technical side of it which is why I'm looking for some credible tests done in a SOMEWHAT credible test. I have a $50 radio shack decibel reader. Even thought it may not be ACTUAL readings, I will use it for the after test so it WILL give me a difference in results.

My concern is windows up, cruise set at 70mph. So that being said I put windows up, no AC no radio and cruise at 70mph....I was between 94dB A scale on flat road and 103dB at slight incline under load. A lot of drone.

I don't have a way to test for the frequency since I don't have access to that equipment but I would assume it's on the lower end of the spectrum which is tougher to eliminate vs high frequency.

Thanks a TON for any pointers/advice!

Dean

[That1Kid]

Peel and seal is shit. Buy a deadener product designed for vehicles.

Butyl > asphalt

[6berry]

go to the second skin section on here and you will see plenty of threads about peal and seal and how it isnt an effective sound deadener. It works for mass loading which isnt effective as the principle second skin uses which is as a constraint layer damper.

[smitty2919]

isn't the whole point of the damplifier type product to add mass and lower the resonant frequency of a panel?? So my immediate guess would be if peel and seal had the same density as damplifier, wouldn't it be close to the same?

[BeatBox]

Here we go again

[tonedeaf]

Peel and seal does NOT have any of the same qualities second skin does. Not even close. To make a difference as a mass loader you'd have to add 4 layers of P&S to make a difference. By that time you'd be easily in the price range of damp if not closer to damp pro, without having to add multiple layers. Sound deadening is also NOT about just mass loading. In fact mass loading is a very inefficient way to deaden panels, which is why all you really need is 25-30% coverage of a panel to really deaden effectively. Damplifier and other REAL quality CAR sound deadening products actually do far more than just add mass to panels. Keep reading on places like here and in the SS section to get hard facts. Peel and seal sucks. Simply put. Spend cash on a box of Alpha damp, and going by the 25% coverage theory, most cars can be effectively sound deadened with just one pack. Doing a build PROPERLY is like building a house. Start with a good foundation and dont skimp, or the house wont last long before you're having to keep fixing the foundation. Do it right the first time ad you wont have to keep redoing it.

[tonedeaf]

Start reading. Ill wait.

http://www.stevemeadedesigns.com/board/topic/112634-why-roofing-products-dont-work/

Because of the recent influx of people wanting to save money by purchasing roofing products, I decided to write a short article as to why these products are not a valid option.

Disclaimer: The views and opinions expressed herein are those of the author and do not necessarily reflect those of Second Skin Audio or this website.

All rights reserved.

Reproduction in whole or in part is strictly prohibited without express consent from the author of this article.

The main three.

When it comes to controlling and eliminating vibrations there are typically three categories of products to choose from. Mass loaders, CLDs and FLDs.

Mass loaders are exactly what they sound like, they add mass to lower the resonance frequency of the panel.

Mass loading was a popular technique in years past, but mass loading is extremely ineffective and is considered old technology. Why? To be effective, mass loading requires approximately four times the weight of the panel to be added to reduce the panels resonance just one octave. This in not an efficient way to control vibrations, not to mention the negative impact it'll have on your gas mileage.

Next up you have CLDs (constrained layer dampers). CLDs work by converting the vibrational energy into low level negligible heat. Because of their efficiency at controlling vibrations, these products are typically thinner and lighter then traditional mass loaders while performing two or three times as well. Thinner, lighter, and less product needed to achieve greater results.

And finally you have FLDs (free-layer dampers), or extensional dampers. These type of products include most liquid vibration products and a few self sticking mat products. The way they work is that vibrational energy is dissipated as a result of extension and compression of the damping material, vs. a cld where the energy is lost through shear deformation of the material.

In most cases CLDs have the upper hand over FLDs because of their ability to maintain a higher loss factor across a wider range of frequencies, temperatures, and thicknesses of the substrate. Basically they are more efficient at controlling vibrations. This is especially true when applications require a light weight solution. For instance on a substrate of say 1/8", a cld mat of only 1/16" may be required to control the vibrations. The FLD on the other hand may require three or four times the thickness, so 3/16 to 1/4", to achieve the same loss factor.

Why roofing materials aren't a suitable product for use in vibration control.

People looking for a cheaper alternative to proper sound deadening seem to flock towards the roofing department at their home improvement stores.

Products that are typically found and used are Peel & Seal and other similarly produced roofing membranes. Often these look and feel similar, if not the same, as actual vibration control products so it becomes an obvious choice. Heck there has even been several companies that went as far as rebadging these roofing products as automotive sound deadening and sell them at a premium. Go capitalism!

The reason these roofing products are not an effective or efficient alternative are many. Most roofing products are made from asphalt or a combination of asphalt, bitumen, petroleum distillates, and/or low grade rubber. These in most any combination equate to a low grade adhesive. Because of this, these products are intended for use on low sloping roofs, typically not exceeding 30°, as their their adhesive is the limiting factor. If you were to apply such product to a vertical surface, such as a car door, failure can be imminent.

Another reason these roofing products are not ideal is the fact that they lack a thick enough constraining layer (foil) to do any good. Without this constraining layer the product can't withstand the shear strain of panel flex and the conversion of the vibrational energy into low level heat is lost.

Even as inefficient as mass loading is, these products wouldn't even cut the mustard as a mass loader because they are just too light weight (averaging about .30 pounds per sq. ft.).

At the end of the day, it's your vehicle and your money. Take the info presented here in this article and make an informed decision.

Later,

[BJD3]

Dude, WTF happened to my post?

Link. In my sig. Anti-Peel and Seal. Click it.

[Parentnoia]

I'll just say this. Put your Mechanical Engineering degree to the side. Car audio is not rocket science, at all. You made my brain hurt reading that. Not from lack of understanding what you meant, but understanding why you think you need to do all this fanciness for car audio.

[tonedeaf]

isn't the whole point of the damplifier type product to add mass and lower the resonant frequency of a panel?? So my immediate guess would be if peel and seal had the same density as damplifier, wouldn't it be close to the same?

Thats what some people think:

it adds mass, same thing the name brand deadeners do...

Wrong PERIOD.

Mass loading is an inefficient method for controlling vibrations.

If this were true, a product like Damplifier which weighs in at .35 pounds per square foot would suck donkey ears, however it out performs products that weigh twice as as much and are twice as thick.

Doesn't matter if it's an inefficient way, it works and at the time it was rather cheap.

So your deadener doesn't add mass????

All products add mass but that is not how properly designed CLD vibration mats are designed to work.

So lumping all "name brand deadeners" into the same category is wrong.